The labours of the Jesuits, however, were eventually more successful than all the military forces which were sent against the Calchaquis. The indefatigable missionaries reduced one tribe after another to a state of comparative civilization, and eventually removed the greater part of them from their native soil to form the nucleus of the Christian settlements which they were anxious to establish upon their own plan on the shores of the Vermejo, amongst the Indians of the Chaco. There they soon lost all importance, and the hostilities of other Indian nations, and a dreadful epidemic which broke out amongst them, in the year 1718, finally put an end to the existence of a gallant people, who had not only signalized their name by their successful wars against the Spaniards, but who, in times long before, had maintained their independence in spite of all the efforts of the dynasty of the Incas of Peru to reduce them to subjection. SALTA is the frontier province of the republic to the north; and follows in geographical succession those of Tucuman and Catamarca, which bound it to the south and west. The river Vermejo and its tributary, the river of Tarija, constitute its limits to the east. It is divided into the four departments of Salta, Jujuy, Oran, and Tarija; the latter of which has been occupied by the Bolivians, apparently with a determination to maintain possession of it. Deducting the population of that department, the rest of the territory of Salta is estimated to contain nearly 60,000 souls. The city of Salta has between 8000 and 9000 inhabitants. It was founded in 1582, by Don Philip de Lerma, Governor of Tucuman, with a view to secure the communication between that province and Peru from being cut off by the hostile Indians. Its latitude is said to be 24° 30´. Upon the whole it has a neat appearance, and boasts of its cathedral and many churches. It is, however, badly situated in the bottom of a valley, through which flow the rivers Arias and Silleta, the latter of which has of late years abandoned its ancient bed, and seems to threaten at no distant period to burst over the low marshy grounds upon which the city stands. Shut in by the mountain ranges in the neighbourhood, the atmosphere is at certain seasons charged with miasma, giving rise to intermittent fevers and agues, which are very general at those periods amongst the inhabitants.